Green’s Dictionary of Slang

colie n.

[Sp. colorado, coloured]

(US Mex. teen/drugs) a depressant.

[US]L. Rodríguez Always Running (1996) 54: Pills they called colies or blancas (colies was short for coloradas, which meant ‘reds’ or downers; blancas stood for ‘whites’, uppers).